jeff4912

I have bought a Multiplex Mentor (4.5lbs) and am being a little over whelmed by all the engine choices. I will have a 11x5.5e prop on this plane and think I want about a 500-600watt motor.
I also have (2) 3S 2200mah 30C 11.1volt batteries that I would like to use on this motor, but I can get new batteries.
From what I have already learned, based on the prop size, people are recommending in the neighborhood of a 1000kv engine.

I have been looking at Turnigy engines among others. I currently use a E-Flite Park450 in another plane but want to try another brand since I am new to this.

Thank you for your input.

xmech2k

Well, here's the recommended system at Tower Hobbies: Multiplex Mentor Power Pack.

I have it in my Mentor and I think it's a good setup, but I use 3s 3300 batts and get 5 minutes, so I don't think you'll be happy with the 2200's, unless you parallel them and put them both onboard. I've seen others put much bigger motors in theirs, like the ones out their crashed E-Flite Carbon-Z Yak, and 4 cell batts. Those are ballistic!

I'm also not comfortable yet with selecting motors, so I usually stick to recommended stuff, or motors that have power specs listed for each prop or I'm likely to get it wrong. Seems to be more an art than a science the way they name their motors. Some people have it figured out though, and hopefully they can be more help.

mixerfix

Sk3 3548-900 or -1000, AXI 2826


---MAV
Marc A Volovic
[email protected]

mixerfix

Sorry - pressed send too soon...

3548 class motors. I heartily suggest 4s batteries, not 3s..

If you want to tow, move to a larger motors, 4240 or 4250. Try to be on the high end of the kv scale for the 42xx..

If you need specific motors/links - drop me a line - I flew the mentor with two 35xx types and two 42xx types.

M


---MAV
Marc A Volovic
[email protected]

jeff4912

I'm looking at the Turnigy SK3 3542 1000kv 45amps 670 watts output for my motor. It's diameter is38mm, will that fit the Mentor?

Also looking at the 3300mah 4S 30C battery...good choice?

Turnigy Plush 60amp esc

This a good combo?

hayofstacks

my ultra stick 25e weighs 3.5 lbs and has a bit over 800watts on 4 cells and a 12" prop. motors choice should start with what fits. a larger prop is much more efficient for thrust. measure the center line of your motor, see how much room you have for a prop.

this will also tell you if you want 3 or 4 cells. I've noticed 4 cells are much more expensive then 3, and depending on your needs, heavier for a shorter flight times.

id see what size prop you can fit. then you might be able to run either a 3 or 4 cell battery depending on what you want.

mixerfix

The 3542 is ~35mm in diameter and ~42mm in can length. The power consumption of some 670w seems a bit high, unless it is a higher kv than you think (i.e. 1250kv or something close).

In any case, the 3542 is, in my opinion, a bit too light for the mentor.

In my opinion, you are better off with either http://www.hobbyking.com/hobbyking/store/__18121__Turnigy_Aerodrive_SK3_3548_1050kv_Brushle ss_Outrunner_Motor.html if you are not towing or with http://www.hobbyking.com/hobbyking/store/__18123__Turnigy_Aerodrive_SK3_4250_500kv_Brushles s_Outrunner_Motor.html if you are towing. Mind - for the second motor, 4s is a bit marginal vis-a-vis speeds.

M


---MAV
Marc A Volovic
[email protected]

mixerfix

Oh - forgot. The plush 60 is quite good. I had great experience with them.

The battery depends on the balance - does your plane balance well. It is close to what I used, if I remember...


---MAV
Marc A Volovic
[email protected]

hayofstacks

http://www.headsuphobby.com/Power-Up...otor-E-590.htm

power up 32 sport.

weighs less then an ounce more then recommended motor, is good for 650.watts on the recommended prop of 11x5 but its 4 cell. if you can fit a 12x6 on 3 cells, the you will still get 4.25 lbs of thrust. you can also re-use your 2200 3 cells in parallel to see how you like it.
best part, at $32, its roughly half of any other motor I could find that I liked in this size, other then hobby king.

and if you get the need for more power, you still have the option of stepping up to 4 or even 5 cells.

mixerfix

Hay - yep, that's a 3548. Looks like a good price, too.

EDIT - data and diagrams do not agree! Is this a 42mm diameter or less? 42mm length or 48mm?

You should contact them before using this.


---MAV
Marc A Volovic
[email protected]

hayofstacks

http://www.headsuphobby.com/Power-Up...otor-E-580.htm

bit lighter, but you'll be stuck on 3.cells in my opinion.

hayofstacks

I'm guessing 42 diameter and 42 length.

he uses the same diagram for different motors to show motor mounts. I've never had a single issue with heads up, and they will answer ANY email right away.

jeff4912

Thanks for all of your input everyone. Its alot to digest.

Just when I think I have it all figured out, I find that propeller size has something to do with engine kv size and batteries etc..

mixerfix

Jeff - the rule of toe is - on a given motor the larger the prop, the slower it will spin and the higher will the current draw be...

For ANY motor you expect to find three pieces of info to guide you:

1. Voltage range - x cells to y cells (where x < y)
2. Prop range - AxB to CxD (where A < C)
3. Kv - rpm per minute per input volt

When behaving like a decent human being (i.e. not killing motors), you normally choose the LARGER prop with the SMALLER cell count.

Example:

http://www.hobbyking.com/hobbyking/store/__18121__turnigy_aerodrive_sk3_3548_1050kv_brushle ss_outrunner_motor.html

1050Kv, 3 to 4 cell battery, and (prop data not there, but I know it) 11x5.5 to 14x7 prop range.

You expect to normally see this motor on 3S with a 13x6.5 prop give or take for 3D and 12x8 for sport flight. You expect to see this motor on 4S with a 12x6 or 12x4 for 3D and 11x5.5 or 11x8 for sport.




---MAV
Marc A Volovic
[email protected]

mixerfix

And kv will be a general guide to power/potential speed...


---MAV
Marc A Volovic
[email protected]

shimsham

Hi. Just a little late joining this discussion,but would a NTM TURNIGY 42 propdrive 42-48 650kv motor be ok for a Multiplex Mentor

Colin

Porcia83

It would work, but a bit overkill. I have had these on two of my Mentors and they scream...push this plane straight up vertical for 300 feet no problem.

http://www.hobbyking.com/hobbyking/s...10Kv_350W.html

I use a 60 amp esc and a 4 cell battery, usually a 2650 or 3300.

It can go on something in the Power 15-25 range as well.

My favorite plane, hands down.

easystar123

I have a Multiplex Mentor on floats and i love it. Its very stable in flight and looks great on the water. I power it with a himax c4220-0510 brushless motor. With a 3s 4250 lipo battery i get good lengthy flight times even with all the lights i have installed on the plane. Anyone thinking about getting a Mentor wont be disappointed as it flys like a trainer and can also perform some basic aerobatics as well.

easystar123

My multiplex mentor float plane at the lake.